Summary: LETTERS
Microbial habitability of the Hadean Earth during the
late heavy bombardment
Oleg Abramov1
& Stephen J. Mojzsis1
Lunar rocks1,2
and impact melts3
, lunar4
and asteroidal meteorites5
,
and an ancient martian meteorite6
record thermal metamorphic
events with ages that group around and/or do not exceed 3.9 Gyr.
That such a diverse suite of solar system materials share this feature
is interpreted to be the result of a post-primary-accretion cataclys-
mic spike in the number of impacts commonly referred to as the
late heavy bombardment (LHB)1­7
. Despite its obvious significance
to the preservation of crust and the survivability of an emergent
biosphere, the thermal effects of this bombardment on the young